It is known to mount an inflatable side airbag module to a vehicle seat. In the event of an impact, the airbag can be rapidly deployed to a position between the occupant and the adjacent vehicle door or body structure. The side airbag functions to dampen and distribute the impact load to reduce injuries. It is desirable that the airbag is fully deployed within around 20 milliseconds from impact.
The vehicle seat comprises a rigid frame to which foam pads are attached. The seat is covered by a layer of material made of vinyl, cloth or leather. The airbag module is connected to the seat frame and comprises a housing, the airbag and an inflator system.
Typically, the deploying airbag is channelled so that it deploys through a tearable seam in the covering material. However, the elasticity of both the covering material and the foam padding can reduce the rate of airbag deployment. Valuable deployment time is lost as the expanding airbag compresses the foam and stretches the covering material. This may also cause the airbag to deploy to a different location from the desired location.
It is known to use a force concentrator that partially surrounds the folded airbag and directs the force of the inflating airbag towards the deployment seam of the seat. Such a system is disclosed in US 2006/0113766. The force concentrator comprises one or more rigid panels. However, the size and position of the panels complicates assembly and locating the device within the seat.